Discussion of Background
Examples of dispensers are described in Patent Applications FR-A-2 778 639, EP-A-0 761 314, FR-A-2 443 980 or in U.S. Pat. No. 3,897,005 or U.S. Pat. No. 3,412,907. These devices suffer principally from at least one handicap associated with their manufacturing cost, ease of use, or with the quality of the spray they are capable of generating. Since the samples are generally not intended for sale, their manufacturing cost should be as low as possible. It is therefore important to have devices whose pieces can be easily mass-produced and which can be fitted together in a simple way. They should furthermore be capable of generating a high quality spray, with characteristics that are as constant as possible.
Furthermore, in particular for perfumes, it is known to provide samples in a small volume container (typically 1.5 ml) having a cylindrical body, especially one made of glass, one end of which is closed by a bottom. The other end is open and accommodates a miniature pump, on top of which there is an actuation component having an orifice for spraying the perfume. Such a system is described in FR-A-2 646 408.
The miniature pump, like pumps fitted to containers with larger dimensions, includes a pump body inside of which a plunger can move between a first position, in which the pump body has a maximum volume, and a second position in which the volume of the pump body is a minimum. The pump body selectively communicates with the container via a riser tube and an intake valve, such as a ball valve. During the phase in which the volume of the pump body is reduced, the intake valve is closed. A delivery valve located upstream of the dispensing orifice, however, is opened under the pressure of the product. The product is dispensed in a sprayed form.
When the user relaxes the pressure being exerted on the actuation component, the plunger is raised by a spring to the first position, hence creating a reduced pressure inside the pump body. In this phase, which is referred to as the filling phase, the intake valve is opened by the reduced pressure prevailing inside the pump body, and the delivery valve is closed. Furthermore, a volume of air corresponding to the volume of product transferred from the container towards the pump body enters the container during this phase via a suitable vent orifice.
Although satisfactory in terms of simplicity of use for the consumer and the quality of the spray which is obtained, this system of a miniature container equipped with a miniature pump suffers from a major drawback associated with its cost and the complexity of handling and assembling small-dimensioned components.
Containers having a movable plunger and dispensing orifice, to pressurize and deliver the product, are also known from U.S. Pat. No. 5,709,320. However, these devices employ plungers which are complex and expensive due, for example, to the use of non-return valves.